/*******************************************************************************
* Copyright (c) 2005 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.gef;
import org.eclipse.swt.widgets.Event;
import org.eclipse.gef.editparts.ZoomManager;
/**
* A MouseWheelHandler that zooms the given viewer.
* Typically, this handler should be registered on a viewer that supports zoom as follows:
* <br>
* <code>
* graphicalViewer.setProperty(MouseWheelHandler.KeyGenerator.getKey(SWT.MOD1),
* MouseWheelZoomHandler.SINGLETON);
* </code>
* @author Pratik Shah
* @since 3.1
*/
public final class MouseWheelZoomHandler
implements MouseWheelHandler
{
/**
* The Singleton
*/
public static final MouseWheelHandler SINGLETON = new MouseWheelZoomHandler();
private MouseWheelZoomHandler() { }
/**
* Zooms the given viewer.
* @see MouseWheelHandler#handleMouseWheel(Event, EditPartViewer)
*/
public void handleMouseWheel(Event event, EditPartViewer viewer) {
ZoomManager zoomMgr = (ZoomManager)viewer.getProperty(ZoomManager.class.toString());
if (zoomMgr != null) {
if (event.count > 0)
zoomMgr.zoomIn();
else
zoomMgr.zoomOut();
event.doit = false;
}
}
}